We need a router for custom roles.
The basic principle:
If RoleType is an AuthorRoleType then import('pages/author/index.php').
Otherwise, import('pages/customRole/index.php')
---
(The routing could get more complex.)

What are your thoughts on the approach outlined in the two patches?
The approach involves a new function in the PKPPageRouter class that is overriden in OMPPageRouter. The custom role's type determines the route.

Just to document what we determined today when we talked about the "user groups" (alias "flexible roles"): If we want user-group-specific URLs then, yes, the right approach would be to extend the page router and let it route the user-group specific page to the canonical role-specific handler. The exact approach depends on the back-end API which Juan will implement.